Magnetic disc drive assemblies of the type using rigid discs generally have been made to use 8 inch discs. It is desirable, however, to provide a disc drive system having even smaller diameter discs without materially effecting the recording capability of the discs. Attempts have been made to reduce the size of floppy discs to about 5 inches in diameter. This disc size has been found to be especially adaptable in many applications where only limited space is available for the disc drive system. Because of the success of the 5 inch floppy discs, a need has arisen for an improved magnetic disc drive system which uses rigid discs with 5 inch diameters.